Nice!Tried this but got some weird error when trying to sort ages. Definetely my fault, but nice to see it could be done!

Got it, thanks! The string before the method is actually the separator. Right. Thanks.

'I'

Question: if n = 1, does this return 'I' or '\nI'? Thanks!

Nicely done!

:D

claps

The problem states that the array has every integer from 1 to n exactly once except for some integer in between, which appears twice. The array that you're testing on doesn't fit this description (it has a 9 but no 6, for example), so the solution doesn't work.

I tried this with: arr = [1, 5, 7, 3, 2, 9, 2, 8]
And it returned 9 instead of 2 :/

Double is used for slicing not indexing

Didn't know you can put if statements like that. Nice!

wow!

i did test multiples times it was always finish faster although its neglible , thanks for knowledge

Clever

Nice solution